In the Ten Commandments as given in Deuteronomy 5, what must Israel not do toward a neighbor's house or field?

Answer: Covet it

Deuteronomy 5:21: "You shall not covet your neighbor's wife... his house or field... or anything that belongs to your neighbor."

“You shall not covet your neighbor’s wife. You shall not covet your neighbor’s house or field, or his manservant or maidservant, or his ox or donkey, or anything that belongs to your neighbor.””— Deuteronomy 5:21 (BSB)